Buggy code:
public class DefaultContainer extends JFrame implements WindowListener , IContainer , IFrameMediatorListener { protected static final int DEFAULT_WIDTH = ( ( int ) ( Math . round ( ( ( Toolkit . getDefaultToolkit ( ) . getScreenSize ( ) . width ) * 0.66 ) ) ) ) ; protected static final int DEFAULT_HEIGHT = ( ( int ) ( Math . round ( ( ( Toolkit . getDefaultToolkit ( ) . getScreenSize ( ) . height ) * 0.66 ) ) ) ) ; private static final int DEFAULT_X = ( ( int ) ( Math . round ( ( ( Toolkit . getDefaultToolkit ( ) . getScreenSize ( ) . width ) * 0.16 ) ) ) ) ; private static final int DEFAULT_Y = ( ( int ) ( Math . round ( ( ( Toolkit . getDefaultToolkit ( ) . getScreenSize ( ) . height ) * 0.16 ) ) ) ) ; private static final Logger LOG = Logger . getLogger ( "org.columba.core.gui.frame" ) ; private DefaultFrameController mediator ; private ViewItem viewItem ; protected ExtendableMenuBar menubar ; protected ExtendableToolBar toolbar ; protected StatusBar statusBar ; protected JPanel contentPane ; protected boolean switchedFrameMediator = false ; private String windowname ; private boolean defaultCloseOperation ; protected EventListenerList listenerList = new EventListenerList ( ) ; public DefaultContainer ( DefaultFrameController mediator ) { } public DefaultContainer ( ViewItem viewItem ) { } protected void initComponents ( ) { <START_BUG> this . setIconImage ( ImageLoader . getImageIcon ( "icon16.png" ) . getImage ( ) ) ; <END_BUG> windowname = "Columba" ; setTitle ( "" ) ; statusBar = new StatusBar ( TaskManager . getInstance ( ) ) ; this . getContentPane ( ) . setLayout ( new BorderLayout ( ) ) ; contentPane = new JPanel ( ) ; contentPane . setLayout ( new BorderLayout ( ) ) ; contentPane . add ( statusBar , BorderLayout . SOUTH ) ; this . getContentPane ( ) . add ( contentPane , BorderLayout . CENTER ) ; initDockingConfiguration ( ) ; toolbar = new ExtendableToolBar ( ) ; setToolBar ( toolbar ) ; addWindowListener ( this ) ; } private void initDockingConfiguration ( ) { } private void createMenuBar ( ) { } public IStatusBar getStatusBar ( ) { } public void setFrameMediator ( final IFrameMediator m ) { } public void switchFrameMediator ( IFrameMediator m ) { } public IFrameMediator getFrameMediator ( ) { } public ViewItem getViewItem ( ) { } public void enableToolBar ( String id , boolean enable ) { } public boolean isToolBarEnabled ( String id ) { } public void loadPositions ( ViewItem viewItem ) { } private void savePositions ( ) { } public void windowActivated ( WindowEvent arg0 ) { } public void windowClosed ( WindowEvent arg0 ) { } public void windowClosing ( WindowEvent arg0 ) { } public void windowDeactivated ( WindowEvent arg0 ) { } public void windowDeiconified ( WindowEvent arg0 ) { } public void windowIconified ( WindowEvent arg0 ) { } public void windowOpened ( WindowEvent arg0 ) { } public JToolBar getToolBar ( ) { } public void extendMenu ( IFrameMediator mediator , InputStream is ) { } public void setContentPane ( JPanel view ) { } public void extendToolbar ( IFrameMediator mediator , InputStream is ) { } public JFrame getFrame ( ) { } public void close ( ) { } public void addToolBar ( JComponent c ) { } public void setToolBar ( JToolBar toolbar ) { } public void setTitle ( String arg0 ) { } public void setWindowName ( String name ) { } public void setCloseOperation ( boolean close ) { } public JPanel getContentPanel ( ) { } public void titleChanged ( FrameEvent event ) { } public void statusMessageChanged ( FrameEvent event ) { } public void taskStatusChanged ( FrameEvent event ) { } public void visibilityChanged ( FrameEvent event ) { } public void layoutChanged ( FrameEvent event ) { } public void closed ( FrameEvent event ) { } public void toolBarVisibilityChanged ( FrameEvent event ) { } public void switchedComponent ( FrameEvent event ) { } public void addListener ( IContainerListener l ) { } public void removeListener ( IContainerListener l ) { } public void fireComponentChanged ( IFrameMediator mediator ) { } }

Fix:
this . setIconImage ( ImageLoader . getMiscIcon ( "icon16.png" ) . getImage ( ) ) ;